Drilling operations have become increasingly expensive as the need to drill deeper, in harsher environments, and through more difficult materials have become reality. Additionally, testing and evaluation of completed and partially finished well bores has become commonplace, such as to increase well production and return on investment.
In working with deeper and more complex wellbores, it becomes more likely that tools, tool strings, and/or other downhole apparatus may become stuck within the bore. In addition to the potential to damage equipment in trying to retrieve it, the construction and/or operation of the well must generally stop while tools are fished from the bore. The fishing operations themselves may also damage the wellbore and/or the downhole apparatus.
Furthermore, downhole tools used in fishing operations are regularly subjected to high temperatures, temperature changes, high pressures, and the other rigors of the downhole environment. Consequently, internal components of the downhole tools may be subjected to repeated stresses that may compromise reliability. Downhole conveyance means, such as a wireline, slickline, e-line, coiled tubing, drill pipe, and/or production tubing, may withstand stresses that may exceed the structural integrity of the downhole tools they deploy.
One such downhole tool, referred to as a jar, may be operable to dislodge a downhole apparatus when it becomes stuck within a wellbore. The jar is positioned in the tool string and/or otherwise deployed downhole to free the downhole apparatus. Tension load is applied to the tool string via the conveyance means to trigger the jar, thus delivering an impact intended to dislodge the stuck portion of the tool string. High tension loads applied by the conveyance means may be within operational parameters of the jar, however, the impacts delivered at such high tension loads may generate stresses exceeding such operational parameters, thus damaging other components of the tool string.